<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Color Blocks</title>
    <style>
        body {
            margin: 0;
        }

        div {
            width: 250px;
            height: 100px;
            border: 5px solid #000;
            color: black;
            font-weight: bold;
            margin: 25px;
        }

        div#d1 {
            background-color: red;
            float: left;
        }

        div#d2 {
            background-color: green;
            float: left;
        }

        div#d3 {
            background-color: blue;
            float: left;
        }
    </style>
</head>
<body>
    <div id="d1">DIV #1</div>
    <div id="d2">DIV #2</div>
    <div id="d3">DIV #3</div>
</body>
</html>
